No, it’s not a misspelling of cynicism.
I’m in historical awe of Charles Sanders Peirce as the father of Pragmatism. Whilst some people sell out for fame or money, he remained true. It took William James to popularise Pragmatism, so committed was Peirce to working out his ideas. Some of his writing is crazily hard to understand, but for sticking to his principles, and for his awesome beard, I salute him.
Synechism (from Greek synechés, “continuous” + -ism, from syn, “together” + échein, “to have”, “to hold”), a philosophical term proposed by C. S. Peirce to express the tendency to regard everything as continuous, and the general theory that the essential feature in philosophic speculation is continuity. It denies that all is merely ideas, and that all is merely matter, and dualism. (Wikipedia)
“It is that synthesis of tychism and of pragmatism for which I long ago proposed the name, Synechism.” (‘Recent Developments of Existential Graphs and their Consequences for Logic’, CP 4.584, 1906)
Random fact: I almost called this blog Tychism.